Arctic sea ice has reached its annual minimum extent for 2023, marking the sixth-lowest year in the satellite record, as reported by scientists from NASA and the National Snow and Ice Data Center (NSIDC). Meanwhile, Antarctic sea ice recorded its lowest maximum extent on record on September 10, when it should have been growing significantly during the darkest and coldest months.
The Arctic’s sea ice, which plays a crucial role in polar ecosystems and global climate, shrank from its peak area of 5.64 million square miles (14.62 million square kilometers) to 1.63 million square miles (4.23 million square kilometers) between March and September 2023. This is approximately 770,000 square miles (1.99 million square kilometers) below the 1981–2010 average minimum.
In contrast, Antarctic sea ice reached its lowest winter maximum extent on September 10, 2023, measuring 6.5 million square miles (16.96 million square kilometers). This is 398,000 square miles (1.03 million square kilometers) below the previous record-low set in 1986.
Researchers are concerned about the melting sea ice in the Arctic, particularly in the Northwest Passage, where ice levels have notably decreased. The warming temperatures have led to earlier spring melting and later autumn freeze-up, resulting in more extended melting seasons.
Notably, as the Arctic warms about four times faster than the rest of the planet, the ice has been getting thinner. This thickness is critical for the survivability of sea ice, and new research, using satellites like NASA’s ICESat-2 (Ice, Cloud, and land Elevation Satellite-2), is monitoring ice thickness year-round.
The cause of the poor growth of Antarctic sea ice remains under investigation, with factors such as El Niño, wind patterns, and warming ocean temperatures potentially contributing. Research indicates that ocean heat is likely playing a significant role in inhibiting cold-season ice growth and enhancing warm-season melting.
The diminishing sea ice in both polar regions contributes to global warming through a process called “ice-albedo feedback.” Sea ice reflects most of the Sun’s energy back into space, but open ocean water absorbs 90% of it. As sea ice decreases, more heat is absorbed, warming the ocean waters and further delaying sea ice growth.
This trend emphasizes the importance of long-term measurements and a deeper of the factors driving these changes in the polar regions.
